This invention relates to a light duty liquid cleaning composition having an improved preservative system and the composition imparts mildness to the skin and is designed in particular for cleaning hard surfaces as well as being effective in removing grease soil and/or bath soil and in leaving unrinsed surfaces with a shiny appearance.
In recent years all-purpose liquid detergents have become widely accepted for cleaning hard surfaces, e.g., painted woodwork and panels, tiled walls, wash bowls, bathtubs, linoleum or tile floors, washable wall paper, etc. Such all-purpose liquids comprise clear and opaque aqueous mixtures of water-soluble organic detergents and water-soluble detergent builder salts. In order to achieve comparable cleaning efficiency with granular or powdered all-purpose cleaning compositions, use of water-soluble inorganic phosphate builder salts was favored in the prior art all-purpose liquids. For example, such early phosphate-containing compositions are described in U.S. Pat. Nos. 2,560,839; 3,234,138; 3,350,319; and British Patent No.1,223,739.
In view of the environmentalist""s efforts to reduce phosphate levels in ground water, improved all-purpose liquids containing reduced concentrations of inorganic phosphate builder salts or non-phosphate builder salts have appeared. A particularly useful self-opacified liquid of the latter type is described in U.S. Pat. No. 4,244,840.
However, these prior art all-purpose liquid detergents containing detergent builder salts or other equivalent tend to leave films, spots or streaks on cleaned unrinsed surfaces, particularly shiny surfaces. Thus, such liquids require thorough rinsing of the cleaned surfaces which is a time-consuming chore for the user.
In order to overcome the foregoing disadvantage of the prior art all-purpose liquid, U.S. Pat. No. 4,017,409 teaches that a mixture of paraffin sulfonate and a reduced concentration of inorganic phosphate builder salt should be employed. However, such compositions are not completely acceptable from an environmental point of view based upon the phosphate content. On the other hand, another alternative to achieving phosphate-free all-purpose liquids has been to use a major proportion of a mixture of anionic and nonionic detergents with minor amounts of glycol ether solvent and organic amine as shown in U.S. Pat. No. 3,935,130. Again, this approach has not been completely satisfactory and the high levels of organic detergents necessary to achieve cleaning cause foaming which, in turn, leads to the need for thorough rinsing which has been found to be undesirable to today""s consumers.
Another approach to formulating hard surface or all-purpose liquid detergent composition where product homogeneity and clarity are important considerations involves the formation of oil-in-water (o/w) microemulsions which contain one or more surface-active detergent compounds, a water-immiscible solvent (typically a hydrocarbon solvent), water and a xe2x80x9ccosurfactantxe2x80x9d compound which provides product stability. By definition, an o/w microemulsion is a spontaneously forming colloidal dispersion of xe2x80x9coilxe2x80x9d phase particles having a particle size in the range of about 25 to about 800 xc3x85 in a continuous aqueous phase.
In view of the extremely fine particle size of the dispersed oil phase particles, microemulsions are transparent to light and are clear and usually highly stable against phase separation.
Patent disclosures relating to use of grease-removal solvents in o/w microemulsions include, for example, European Patent Applications EP 0137615 and EP 0137616xe2x80x94Herbots et al; European Patent Application EP 0160762xe2x80x94Johnston et al; and U.S. Pat. No. 4,561,991xe2x80x94Herbots et al. Each of these patent disclosures also teaches using at least 5% by weight of grease-removal solvent.
It also is known from British Patent Application GB 2144763A to Herbots et al, published Mar. 13,1985, that magnesium salts enhance grease-removal performance of organic grease-removal solvents, such as the terpenes, in o/w microemulsion liquid detergent compositions. The compositions of this invention described by Herbots et al. require at least 5% of the mixture of grease-removal solvent and magnesium salt and preferably at least 5% of solvent (which may be a mixture of water-immiscible non-polar solvent with a sparingly soluble slightly polar solvent) and at least 0.1% magnesium salt.
However, since the amount of water immiscible and sparingly soluble components which can be present in an o/w microemulsion, with low total active ingredients without impairing the stability of the microemulsion is rather limited (for example, up to about 18% by weight of the aqueous phase), the presence of such high quantities of grease-removal solvent tend to reduce the total amount of greasy or oily soils which can be taken up by and into the microemulsion without causing phase separation.
The following representative prior art patents also relate to liquid detergent cleaning compositions in the form of o/w microemulsions: U.S. Pat. Nos. 4,472,291xe2x80x94Rosario; 4,540,448xe2x80x94Gauteer et al; 3,723,330xe2x80x94Sheflin; etc.
Liquid detergent compositions which include terpenes, such as d-limonene, or other grease-removal solvent, although not disclosed to be in the form of o/w microemulsions, are the subject matter of the following representative patent documents: European Patent Application 0080749; British Patent Specification 1,603,047; 4,414,128; and 4,540,505. For example, U.S. Pat. No. 4,414,128 broadly discloses an aqueous liquid detergent composition characterized by, by weight:
(a) from about 1% to about 20% of a synthetic anionic, nonionic, amphoteric or zwitterionic surfactant or mixture thereof;
(b) from about 0.5% to about 10% of a mono- or sesquiterpene or mixture thereof, at a weight ratio of (a):(b) lying in the range of 5:1 to 1:3; and
(c) from about 0.5% about 10% of a polar solvent having a solubility in water at 15xc2x0 C. in the range of from about 0.2% to about 10%. Other ingredients present in the formulations disclosed in this patent include from about 0.05% to about 2% by weight of an alkali metal, ammonium or alkanolammonium soap of a C13-C24 fatty acid; a calcium sequestrant from about 0.5% to about 13% by weight; non-aqueous solvent, e.g., alcohols and glycol ethers, up to about 10% by weight; and hydrotropes, e.g., urea, ethanolamines, salts of lower alkylaryl sulfonates, up to about 10% by weight. All of the formulations shown in the Examples of this patent include relatively large amounts of detergent builder salts which are detrimental to surface shine.
U.S. Pat. No. 5,082,584 discloses a microemulsion composition having an anionic surfactant, a cosurfactant, nonionic surfactant, perfume and water; however, these compositions are not light duty liquid compositions.
The present invention relates to a light duty liquid detergent compositions with high foaming properties, containing a nonionic surfactant, a sulfonate or sulfate surfactant, an ethoxylated alkyl ether sulfate surfactant, an inorganic magnesium salt, polyethylene glycol, an improved preservative system and water. The compositions may also optionally contain from 0 to 10% of an alkyl monoalkanol amide, an alkyl dialkanol amide, an amine oxide, a zwitterionic surfactant and/or alkyl polyglucoside surfactant.
Nonionic surfactants are in general chemically inert and stable toward pH change and are therefore well suited for mixing and formulation with other materials. The superior performance of nonionic surfactants on the removal of oily soil is well recognized. Nonionic surfactants are also known to be mild to human skin. However, as a class, nonionic surfactants are known to be low or moderate foamers. Consequently, for detergents which require copious and stable foam, the application of nonionic surfactants is limited. There have been substantial interest and efforts to develop a high foaming detergent with nonionic surfactants as the major active ingredient. Yet, little has been achieved.
The prior art is replete with light duty liquid detergent compositions containing nonionic surfactants in combination with anionic and/or betaine surfactants wherein the nonionic detergent is not the major active surfactant, as shown in U.S. Pat. No. 3,658,985 wherein an anionic based shampoo contains a minor amount of a fatty acid alkanolamide. U.S. Pat. No. 3,769,398 discloses a betaine-based shampoo containing minor amounts of nonionic surfactants. This patent states that the low foaming properties of nonionic detergents renders its use in shampoo compositions non-preferred. U.S. Pat. No. 4,329,335 also discloses a shampoo containing a betaine surfactant as the major ingredient and minor amounts of a nonionic surfactant and of a fatty acid mono- or di-ethanolamide. U.S. Pat. No. 4,259,204 discloses a shampoo comprising 0.8-20% by weight of an anionic phosphoric acid ester and one additional surfactant which may be either anionic, amphoteric, or nonionic. U.S. Pat. No. 4,329,334 discloses an anionic-amphoteric based shampoo containing a major amount of anionic surfactant and lesser amounts of a betaine and nonionic surfactants.
U.S. Pat. No. 3,935,129 discloses a liquid cleaning composition based on the alkali metal silicate content and containing five basic ingredients, namely, urea, glycerin, triethanolamine, an anionic detergent and a nonionic detergent. The silicate content determines the amount of anionic and/or nonionic detergent in the liquid cleaning composition. However, the foaming property of these detergent compositions is not discussed therein.
U.S. Pat. No. 4,129,515 discloses a heavy duty liquid detergent for laundering fabrics comprising a mixture of substantially equal amounts of anionic and nonionic surfactants, alkanolamines and magnesium salts, and, optionally, zwitterionic surfactants as suds modifiers.
U.S. Pat. No. 4,224,195 discloses an aqueous detergent composition for laundering socks or stockings comprising a specific group of nonionic detergents, namely, an ethylene oxide of a secondary alcohol, a specific group of anionic detergents, namely, a sulfuric ester salt of an ethylene oxide adduct of a secondary alcohol, and an amphoteric surfactant which may be a betaine, wherein either the anionic or nonionic surfactant may be the major ingredient.
The prior art also discloses detergent compositions containing all nonionic surfactants as shown in U.S. Pat. Nos. 4,154,706 and 4,329,336 wherein the shampoo compositions contain a plurality of particular nonionic surfactants in order to effect desirable foaming and detersive properties despite the fact that nonionic surfactants are usually deficient in such properties.
U.S. Pat. No. 4,013,787 discloses a piperazine based polymer in conditioning and shampoo compositions which may contain all nonionic surfactant or all anionic surfactant.
U.S. Pat. No. 4,671,895 teaches a liquid detergent composition containing an alcohol sulfate surfactant, a nonionic surfactant, a paraffin sulfonate surfactant, an alkyl ether sulfate surfactant and water but fails to disclose an alkyl polysaccharide surfactant.
U.S. Pat. No. 4,450,091 discloses high viscosity shampoo compositions containing a blend of an amphoteric betaine surfactant, a polyoxybutylene polyoxyethylene nonionic detergent, an anionic surfactant, a fatty acid alkanolamide and a polyoxyalkylene glycol fatty ester. But, none of the exemplified compositions contains an active ingredient mixture wherein the nonionic detergent is present in major proportion, probably due to the low foaming properties of the polyoxybutylene polyoxyethylene nonionic detergent.
U.S. Pat. No. 4,595,526 describes a composition comprising a nonionic surfactant, a betaine surfactant, an anionic surfactant and a C12-C14 fatty acid monethanolamide foam stabilizer.
However, none of the above-cited patents discloses a liquid detergent composition containing a nonionic surfactant, an anionic or sulfate sulfonate surfactant, an ethoxylated alkyl ether sulfate surfactant, an improved preservative system, an inorganic magnesium salt, polyethylene glycol and water and optionally an alkyl monoalkanol amide such as an alkanol monoethanol amide (LMMEA), a zwitterionic surfactant, an amine oxide and/or an alkyl polyglucoside surfactant, and the composition does not contain gluconic acid, ethylene diaminetetraacetate sodium salt, isothiazolones, 1,3-dimethylol-5,5-dimethylhydantoin, 5-bromo-5-nitro-1,3dioxane, any abrasives, silicas, alkaline earth metal carbonates, alkyl glycine surfactant, cyclic imidinium surfactant, alkali metal carbonates or more than 3 wt. % of a fatty acid or its salt thereof, a nitrogenous buffer selected from the group consisting of ammonium or alkaline carbonates, quanidine derivatives, alkoxyl alkylamines, and alkyleneamines, and a grease release agent which is an ethoxylated maleic anhydride-alpha-olefin copolymer having a comblike structure with both hydrophobic and hydrophilic chains and the copolymer is characterized by the formula: 
wherein n is about 5 to about 14, x is about 7 to 19, and y is of such a value as to provide a molecular weight about 10,000 to about 30,000.
This invention relates to a light duty liquid detergent composition containing at least two surfactants selected from the group ocnsisting of nonionic surfactants, a sulfate or sulfonate anionic surfactants, an ethoxylated alkyl ether sulfate surfactants, alkyl polyglucoside surfactants, zwitterionic surfactants, amine oxide surfactants, and alkyl monoalkanol amide surfactants and mixtures thereof, an improved preservative system, and optionally, polyethylene glycol, and/or an inorganic magnesium salt and water, wherein the composition does not contain gluconic acid, ethylene diamine tetraacetate sodium salt, isothiazolones, 1,3-dimethylol-5,5-dimethylhydantoin, 5-bromo-5-nitro-1,3dioxane, any silicas, abrasives, alkali metal carbonates, alkaline earth metal carbonates, alkyl glycine surfactant, cyclic imidinium surfactant, or more than 3 wt. % of a fatty acid or salt thereof, wherein the improved preservative system comprises a mixture of 2-bromo-2-nitropropane-1,3diol and tetrasodium iminodisuccinate.
An object of this invention is to provide a novel light duty liquid detergent with desirable high foaming and cleaning properties which is mild to the human skin and has an improved preservative system.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the foregoing and other objects and in accordance with the purpose of the present invention, as embodied and broadly described herein the novel, high foaming light duty liquid detergent of this invention comprises a water soluble, ethoxylated nonionic surfactant, polyethylene glycol, an ethoxylated alkyl ether sulfate surfactant, a sulfate or sulfonate anionic surfactant, an improved preservative system, an inorganic magnesium salt and water and optionally an alkyl monoalkanol amide, amine oxide, zwitterionic surfactant and/or alkyl polyglucoside surfactant, wherein the composition does not contain gluconic acid, ethylene diamine tetraacetate sodium salt, 5-bromo-5-nitro-1,3dioxane, isothiazolones, imino dissucinate-sodium salt, any silicas, abrasives, alkali metal carbonates, alkaline earth metal carbonates, alkyl glycine surfactant, cyclic imidinium surfactant or more than 3 wt. % of a fatty acid or salt thereof, a nitrogenous buffer selected from the group consisting of ammonium or alkaline carbonates, quanidine derivatives, alkoxyl alkylamines, and alkyleneamines, and a grease release agent which is an ethoxylated maleic anhydride-alpha-olefin copolymer having a comblike structure with both hydrophobic and hydrophilic chains and the copolymer is characterized by the formula: 
wherein n is about 5 to about 14, x is about 7 to 19, and y is of such a value as to provide a molecular weight about 10,000 to about 30,000.